A. Field of Invention
This invention generally relates to methods and apparatuses concerning pneumatic tires and more specifically to methods and apparatuses concerning a puncture sealant laminate for pneumatic tires.
B. Description of the Related Art
It is well known that when a pneumatic tire is punctured, such as by a nail or other sharp object, it loses its air pressure and thus loses its ability to perform adequately. Such a punctured pneumatic tire is commonly referred to as a “flat tire.”
To minimize the damage caused by such a puncture, it is known to provide puncture sealants, typically made of puncture sealing rubber or plastic material, onto the crown portion of a pneumatic tire. When a pneumatic tire with a puncture sealant is punctured, the puncture sealant forms a seal around the corresponding opening in the tire to minimize the loss of air pressure.
One problem with known puncture sealants, however, is that they are not recommended for higher speed tires because of the cold flow properties of the sealant material. The sealant material tends to migrate within the tire due to gravity during storage of the tire or when the vehicle that has the tire mounted to it is parked. This migration occurs because when the pneumatic tire with puncture sealant material is cured or vulcanized, the sealant material is depolymerized and thus can flow circumferentially or from side to side within the pocket created in the tire for the sealant material.
What is needed is a puncture sealant that effectively forms a seal during a puncture but does so in a way that minimizes known disadvantages.